128321256 has 64 divisors (see below), whose sum is σ = 368064000. Its totient is φ = 36520128.

The previous prime is 128321243. The next prime is 128321257. The reversal of 128321256 is 652123821.

It is not an unprimeable number, because it can be changed into a prime (128321257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46195 + ... + 48893.

It is an arithmetic number, because the mean of its divisors is an integer number (5751000).

Almost surely, 2^128321256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128321256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184032000).

128321256 is an abundant number, since it is smaller than the sum of its proper divisors (239742744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128321256 is a wasteful number, since it uses less digits than its factorization.

128321256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2998 (or 2994 counting only the distinct ones).

The product of its digits is 5760, while the sum is 30.

The square root of 128321256 is about 11327.8972452967. The cubic root of 128321256 is about 504.3896897982.

The spelling of 128321256 in words is "one hundred twenty-eight million, three hundred twenty-one thousand, two hundred fifty-six".